It's perfectly reasonable to ask moral questions about killing animals. It's not a trivial issue. But it's also perfectly reasonable to ask whether all animals are morally equal. You say that in the eyes of God, all being are equal. But even taking it as given that there's a God, I don't see much reason to believe that. And in any case, trying to sort out what God might think about things is a slippery route to moral conclusions. What matters isn't what God's conclusions might be; what matters are the reasons.
In many cultures, it's common to eat insects—ants, for example. Do we really think that killing an ant and killing a human being are morally on the same level? It's not obvious that they are. Ants are alive; there's no doubt of that. But so are bacteria. So are lettuce plants. We don't think that it's wrong to kill something simply because it's alive, and so among living things there must be distinctions—features of the living beings that make it more or less wrong, or even not wrong at all...

Pets already can't decide whether whether they want to eat kibble, whether they want to be walked on a leash, whether they want to stay indoors most of the day, whether they want to hold their water in until their owners get home, whether they want to be spayed or neutered, nor, for that matter, whether they want to be pets at all.
Pets are different in a lot of ways from their undomesticated counterparts. If interfering with their "natural behavior" is wrong, then keeping pets at all is already a problem. So long as the vegan pet food is nutritionally adequate and doesn't cause the animal any distress, it's hard to see why it would be more wrong (if wrong at all) than any of the other things we've mentioned.

It's a very interesting question. It's about what my colleague Dan Moller calls moral risk. And it's a problem not just for utilitarians. The general problem is this: I might have apparently good arguments for thinking it's okay to act in a certain way. But there may be arguments to the contrary—arguments that, if correct, show that I'd be doing something very wrong if I acted as my arguments suggest. Furthermore, it might be that the moral territory here is complex. Putting all that together, I have a reason to pause. If I simply follow my arguments, I'm taking a moral risk.
Now there may be costs of taking the risks seriously. The costs might be non-moral (say, monetary) or, depending on the case, there may be potential moral costs. There's no easy answer. Moller explores the issue at some length, using the case of abortion to focus the arguments. You might want to have a look at his paper HERE .
A final note: when we get to bacteria, I think the moral risks are low enough to be discounted. I...

I'm puzzled. Why would doing something more "self-involved" be morally better than keeping a pet? Perhaps by "self-involved," you mean self-improving, but morality doesn't call for spending all our time improving ourselves. And even insofar as it does, caring for a pet might help some people to become more empathetic and responsible. Of course, pets sometimes cause problems. But so do cars, DVD players, the computer you wrote your question on, and—for that matter—friends and family. And in any case, morality doesn't call for avoiding all problems. If anything, it arguably calls for the opposite, since if we spend all our time steering clear of difficulties, we're likely to end up stunted and selfish. Some pets probably don't reciprocate affection; goldfish almost certainly don't, for example. But once again, what of it? Even if a fish-fancier agrees that her fish don't fancy her, how would that make her a worse person? Maybe I'm missing something, but I'd have thought the moral questions...

I'm having trouble seeing what evolution has to do with it. Many animals, Singer supposes, feel pain. Pain (roughly; the refinements won't matter here) is intrinsically bad, no matter what sort of creature experiences it. Whether animals (or humans) feel pain because of evolution, because a God made them that way, or because we're all sentient animaldroids, designed by mad scientists from Mars is beside the point. Singer's thought is that pain is bad for us, and animals are no different from us in that respect. He isn't making a point about the phylogenetic tree. Cabbages don't feel pain; cats do. So when we're calculating the balance of pleasure to pain, the cat's pain (or pleasure) should be included in the calculation. But since cabbages aren't sentient (so far as we know), there's nothing about the cabbage to add or subtract.

I agree with Andrew: the dog/pig distinction won't get us anywhere. And I might even be persuaded that we shouldn't eat animals at all. But there's a sliver of a distinction that may be worth noting. If a stranger asks me to drive him to the grocery store, I don't have any obligation to say yes. If my friend asks me (and if it's not a lot of trouble to do it) then it's not so clearly okay for me just to say no. If my daughter asks me, the obligation seems even stronger. Our relationships with people can make a difference to how we ought to treat them. We can and do have relationships with our companion animals. And those relationships could make a difference to how we should treat them. I have an obligation to feed my dog, for example, but not to feed yours. Now it may very well be that it's wrong to eat animals at all. But even if it's okay to eat animals in general, it doesn't simply follow that it's okay to eat my own pet and the fact that it's my pet is the reason why it doesn't follow....

There's no clear reason why animals shouldn't have rights. After all, humans are animals and on our usual view, even infants and the severely mentally disabled have at least some rights. Certain rights – for example, the right to sign a contract – presuppose certain abilities and so non-human animals typically won't have those. Other rights don't presuppose any abilities and non-human animals might well have at least some of those. The right not to be tortured is a plausible example. Which rights animals have is controversial. To this we can add that there's a lot of controversy about exactly what rights are . On that question, you might find it useful to take a look at this article from the Stanford Encyclopedia of Philosophy. But for some issues, the notion of rights may be less important than it might seem. For example, someone might reasonably be persuaded that they shouldn't eat animals even if they're not sure that this is a matter of the rights of the animals. This isn't to say...

Like a great many words, "vegetarian" doesn't have a fully-precise meaning; it almost certainly means slightly different things in different contexts and when used by different people. Take your case of the person who just "happens" not to eat meat - not by design, not on principle, but just as it turns out. Whether we call this person a vegetarian or not isn't something that usage fully settles. We might, for example, call them a " de facto vegetarian" as opposed to a "deliberate vegetarian." Part of what we generally mean when we use the word "vegetarian" has to do with what people actually eat, and part has to do with what their intentions are, but there's no simple formula here. A person who intends not to eat meat but eats it accidentally from time to time (e.g., because of misleading labels) would probably count as a vegetarian by most people's standards. If the accidents were frequent enough, many people might hesitate to call the person a vegetarian and would qualify what they say. ...

Yes, because we are animals and we can do both. But as for non-human animals, the answer depends on whether they're like us in relevant respects. In the case of anticipation, the answer at least seems to be yes. Think of a dog getting visibly excited as you get the can of food from the cupboard, for example. Hope is more complicated because to hope, the animal would have to represent something as possible, want it, and also represent the possibility that it might not be forthcoming. Whether there are non-human animals with that kind of cognitive sophistication is not clear, and it's also not clear for animals without language what sorts of experiments or observations would help us figure it out. However, it's an interesting question, and psychologists are generally much cleverer at designing experiments than philosophers are. So perhaps some day we'll know.

A man points a gun and pulls the trigger. The gun fires, and the bullet strikes another man in the head, killing him instantly. Was it murder? Anyone who thinks they can answer the question based on what's been said so far doesn't understand the word "murder." Did the man who pulled the trigger do something wrong? Anyone who thinks they can answer the question based on what's been said so far doesn't understand what it means for something to be wrong. Whether what happened was a murder, and whether anyone did anything wrong depends on a lot that's been left out, not least a lot about who intended to do what and who knew or believed what. Scenario #1. The man who pulled the trigger is a hit man. The person shot was an otherwise innocent witness to a crime. The person who hired the hit man wants to be sure the witness can't testify. This murder and the man who pulled the trigger (as well as the one who hired him) did something deeply wrong. Scenario #2: The man who pulled the trigger is a police...